In this project, MicroFab will build a prototype system capable of depositing matrix solutions onto the tissue sections with high resolution using picoliter volumes (nanoliter volumes via the accretion of drops) for the purposes of MALDI MS imaging. The system will be very flexible in terms of amount of matrix deposited per spot, distribution of the matrix on the tissue sample, and the matrix spot pitch and placement. The system will provide capability for overprinting additional matrix solution and/or solvents and surfactants onto previously deposited matrix spots to improve analyte extraction from the protein sample. We will optimize the formulation of the matrix solutions to achieve the most reliable microdispensing, while maintaining functionality for the imaging process. The actual coating process will be verified by deposition onto tissue sections with evaluation by MALDI-TOF MS. The matrix coating platform is an automated tool for the precise microdeposition of matrix solutions onto tissue samples for MALDI MS imaging. The array of discrete matrix spots significantly reduces the lateral migration of protein on the surface of the tissue section, while increasing the analyte extraction per area, resulting in a greater resolved protein image. [unreadable] [unreadable] [unreadable]